Underground utility vault with a ventilator-type grate



J. B. SCHACK 3,479,777

Y VAULT WITH A VENTlLA'IOR-TYPE GRA'TZ Nov. 25, 1969 UNDERGROUND UT ILIT Filed March 22, 1968 FIG IZNWENTOR. JOHN B. SCHAOK ATTORNE Y5 FIG United States Patent O 3,479,777 UNDERGROUND UTILITY VAULT WITH A VENTILATOR-TYPE GRATE John B. Schaclr, Auburn, Wash., assignor to Concrete Conduit Company, Inc., Auburn, Wash., a corporation of Washington Filed Mar. 22, 1968, Ser. No. 715,291 Int. Cl. E02d 29/14; E04c 2/42 US. C]. 5220 7 Claims ABSTRACT OF THE DISCLOSURE Underground utility vaults for underground electrical or telephone systems often require an atmosphericallyexposed opening for ventilation that must be covered by a grate structure. Typical of such gate structures is the well-known crossed rod or bar configuration which covers the opening and yet permits passage of air into and from the vault. Unfortunately, such structures also permit the insertion of elongated objects into the vault, to the possible damage of equipment housed therein or of the person inserting the object.

A primary objective of the present invention is to provide an underground utility vault structure wherein a grate is provided to cover an exposed opening thereof in such a manner as to maximize ventilation therethrough without permitting entry of elongated objects through the vault opening. A further objective is to provide a reinforced grate structure of low weight and high strength. These and other objects and advantages of this invention will become apparent from a consideration of the following discussion in conjunction with the accompanying drawings of which:

FIG. 1 is a top plan view of a preferred embodiment of the grate structure of this invention in place over a vault opening;

FIG. 2 is a vertical cross sectional detail view taken along the line 22 in FIG. 1; and

FIG. 3 is a vertical cross sectional detail view taken along the line 33 in FIG. 1.

The grate structure of the present invention comprises an upper grillwork and a lower ventilator structure depending from the grillwork with a reinforced midsection in load-bearing contact with the midsection of the overhead grillwork.

Referring to the figures, the grate structure of this invention comprises a grillwork formed by a plurality of rectangular cross bars 10 and a plurality of cross rods 12, and a ventilator comprising a plurality of chevron baifles 14 extetnding between chevron side plates 16.

The cross bars 10 are positioned on edge equidistantly parallel to one another. The cross rods 12 extend equidistantly parallel to one another and at right angles to the cross bars 10 through apertures provided therefor in the cross bars 10 to maintain the desired spacing between the cross bars 10. The cross rods may have either a circular cross section or a hexagonal or like geometric cross section.

The elongated chevron bafiles 14 are divided into two sets with the bafl'les in each set positioned on edge, equidistantly parallel to one another, and opening outward from the longitudinal center of the ventilator structure.

The longitudinal midsection of the ventilator structure is occupied by a delta beam 18, the sides of which form chevron baflles opening outward with abutting apexes welded or otherwise rigidly connected together. Horizontal top and bottom elongated rectangular plates span the top and bottom edges of the delta beam side walls to complete the beam. The delta beam 18 is an integral unit rigidly attached to the baflle side plates and extends across the grate structure in load-supporting contact with the underside of the cross bars 10. This construction lends substantial strength to the grate structure and also permits a maximum of open area to be exposed for ventilation purposes.

Each bafile' side plate 16 is Z-shaped with a vertical trapezoidal face 16c having inwardly sloped ends 16a, a narrow, inward turned baffle-supporting flange 16a and a narrow, outwardly turned cross bar-contacting flange 16b. The upper edges of the baflles abut the undersides of the cross bars 10 and are suitably connected thereto by welding or otherwise. The ends of the baffle lower edges rest on the inwardly turned flanges 16a and are suitably connected thereto by welding or otherwise. The baffle ends abut the inner faces of the side plates 16 and are suitably connected thereto by welding or otherwise. End bafiles 2020 are positioned as shown with an upper leg arranged parallel to the upper legs of the chevron battles 14 and a curved lower end section that opens outward and terminates even with the adjacent baffle plate sloped end 16d.

The inner edges of the vault side walls 30 that define the opening to be covered are rabbeted at the top as shown such that the grillwork is inset flush with the top edge of the vault opening. The inset vault ledges that are oriented perpendicular to the cross bars 10 are sufliciently wide to supportably receive the ends of such cross bars and the inset vault ledges that are oriented parallel to the cross bars 10 are sufficiently wide to supportably receive at least one such cross bar.

Bolt flanges 32 are provided in the grillwork to overlie the inset vault ledges and bolts 34 extend therethrough into the vault side walls to hold the grillwork in place. The bolt flanges are each welded between two cross bars 10 with an intermediate cross bar foreshortened to abut the side of the bolt flange as shown. The bolt flanges are positioned intermediate the upper and lower edges of the cross bars 10.

The upper and lower edges of each chevron baflle define a vertical plane that is intersected by the apex of the adjacent baffle. Thus, an elongated object such as a stick or rod cannot be extended through the grate structure. Furthermore, the baffle side plates 16-16, by reason of their upper flanges 16b extending outward such that they are supportably carried by the adjacent vault side wall ledges and by reason of the upper edges of the outermost end baffies 2020 being positioned in close adjacency to the inner edge of the adjacent vault side Wall ledges, the structure prevents the intrusion of elongated objects through the grate structure at the sides thereof. These aforementioned structural features make it substantially impossible for a child, for example, to either damage, or be harmed by, any electrical equipment contained within the vault.

The thickness of spacing of the chevron bafiies 14, the cross rods 12 and the cross bars 10 are designed such that the ventilating area through the ventilator structure is substantially matched to the ventilating area through the grillwork for maximum ventilating efliciency. In a preferred example of the invention, x 1'' cross bars 10 are placed on centers, A" hexagonal cross rods 12 are placed on 4 centers, and together occupy approximately 76% of the vault opening area. By providn b ttl i /16? h pk. t br w q f m 1. au e 1. In an underground utility vault having an exposed I opening therein, a grate structure covering said opening and comprising a plurality of cross bars extending across said opening parallel to one another, a plurality of cross rods extending parallel to one another through said crossbars to maintain the spacing of said cross bars,

said cross bars and cross rods defining a grillwork struc- .ture; a pair of bafile side members depending from said grillwork structure into said opening, a load-supporting beam structure extending between the midpoints of said structure to provide a plurality of ventilating passages communicating with the underside of said grillwork structure, said baffie side plate members, bafile members and beam structure defining a ventilator structure.

2. The structure of claim 1 wherein said load-supporting beam structure comprises a delta beam having outwardly-opening chevron-shaped side walls positioned on edge and rigidly joined together at their abutting apexes, and top and bottom plate members extending the length of said side wall and rigidly interconnecting the respective edges of said side walls.

3. The structure of claim 1 wherein said baflle members comprise elongated chevron-type bafiles positioned on edge with the baflles on opopsite sides of the bafile side plate midpoints being oppositely-oriented to open outward toward the adjacent edge of said grate.

. .4.- Ih ructuer of lai rtfirwherein said load-supporting beam structure comprises a delta beam having outwardly-opening chevron-shaped side walls positioned on edge and rigidly joined together at their abutting apexes, and top and bottom plate members extending the length of said side walls and rigidly interconnecting the respective edges of said side walls.

5. The structure of claim 4 wherein said bafile members and. said delta beam side Walls have substantially parallel upper and lower legs with the apexes of the chevron-shaped members extending at least to the plane defined by the upper and lower edges of the adjacent chevron-shaped members to prevent direct access through said grate from without.

6. The structure of claim S-wherein the number and position of said baflle members is selected such that the total open area of said ventilator structure measured perpendicular to the walls of said bafile members closely matches the total open area of said grillwork.

7. The structure of claim 1 wherein said baffie side members have an upper flange extending outwardly to overlay the edge of said vault opening, and have a generally-vertical face connected to the ends of said bafile members such that access to said vault opening outward of said baffle plate members is prevented.

References Cited UNITED STATES PATENTS 1,180,431 4/1916 Ritter 52666 1,390,347 9/1921 Elliston 98l 14 X 1,652,128 12/1927 Hare 52473 X 2,211,568 8/1940 Henney 98l2l 2,987,985 6/1961 Johnson 52473 X 3,256,670 6 /1966 Tersigni 52666 X 3,390,225 6/1968 Couch et a1. 52--20 X FRANK L. ABBOTT, Primary Examiner P. C. PAW, JR., Assistant Examiner U.S. c1. X.R.' 

